22.允许重复的容器(unordered_multiset)

 #include <string>
 #include <iostream>
 #include <unordered_set>
 using namespace std;

 void main()
 {
     unordered_multiset<string> myset{ "pig", "pig", "pig" ,"chicken"};
     /*for (auto i : myset)
     {
         cout << i << endl;
     }*/

     auto it = myset.equal_range("pig");

     //输出所有重复数据
     //it.first链表的起点 it.second链表的终点
     for (auto ib = it.first, ie = it.second; ib != ie; ib++)
     {
         cout << *it.first << endl;
     }

     cin.get();
 }